diff --git a/python/adapters/brcm_openomci_onu/heartbeat.py b/python/adapters/brcm_openomci_onu/heartbeat.py
index ffe4b69..386d0ab 100644
--- a/python/adapters/brcm_openomci_onu/heartbeat.py
+++ b/python/adapters/brcm_openomci_onu/heartbeat.py
@@ -12,6 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+from __future__ import absolute_import
 import structlog
 from twisted.internet import reactor
 from twisted.internet.defer import inlineCallbacks